The present invention relates to a method of manufacturing a coil of a continuous, flexible object, in particular hosing, flexible tubing, rope and the like, and enveloping the coil to form a parcel for delivery to a user of the object, said object being coiled onto an axially open core to produce said coil, said method comprising the steps of:
a) bringing the core to be fixed by a tool so that it is firmly clamped between two parallel support rings of the tool and centered by a centering element in each support ring, whereby a rotatable unit is formed, PA1 b) attaching said object to said unit and bringing the unit to rotate in a coiling machine so that the object is wound to form said coil, and PA1 c) when the object has been cut, bringing a plurality of continuous straps to surround the core from the inside thereof, and the coil enclosing the core, without engagement with the support rings, after which the straps are tightened and secured to form said parcel. The invention also relates to a core of a rotatable unit for manufacturing a coil of a continuous flexible object, in particular hosing, flexible tubing, rope or the like, and enveloping the coil to form a parcel for delivery to a user of the object.
Such hosing and flexible tubing used, for instance, for laying fibre optic cable, is delivered in rolls, known as coils, where small quantities are concerned. The roll is free from core and wrapping and is held together by a number of straps. At the application site the roll is placed on a special device to enable the hosing to be rolled off when the straps have been cut, or the roll is placed on the ground, the straps cut and the hosing pulled out, which is relatively inconvenient. This technique is therefore limited to deliveries of shorter lengths of hosing.
Conventional wooden drums are used for delivery of particularly longer lengths of hosing and flexible tubing, e.g. lengths of 500-2000 meter. Since these hosing and tubing products require a relatively large radius to allow bending, wooden drums must be chosen that have cores with a diameter of about 1 meter and more, referring to the inner cylindrical part. The size of the wooden drum will therefore be necessarily considerable, entailing high costs for manufacture and handling of the wooden drum. When the hosing or flexible tubing is delivered on wooden drums at the use site, the wooden drum is mounted on special equipment for unwinding and pulling out the hosing or tubing. The wooden drum is often skew and the hosing or tubing is thus pulled off jerky so that the work takes longer. Furthermore, the empty wooden drum must be returned to be used for a new delivery of hosing or tubing. This increases the total handling costs and the repeated use of the wooden drum, entailing wear and rough treatment, may contribute to it becoming skew.
SE-9101042-1 describes a special system for handling continuous, flexible objects such as hosing or flexible tubing, said handling commencing with the manufacture of a coil of cable or cord and enveloping the coil to form a parcel for delivery to a user. The coil is obtained by the object being wound onto an axially open, cylindrical sleeve. Before coiling is performed, the sleeve is provided with two flat, outer protective rings having concentric support surfaces cooperating with opposite internal or external surfaces of the sleeve depending on which form of protective rings are used. The sleeve is then fixed by a tool which has two parallel support rings with centering elements facing each other so that the sleeve is clamped between the support rings and centered by their centering elements so that a rotatable unit is formed. The object is then attached to said unit and the unit is brought to rotate in a coiling machine so that the object is wound to form a coil. The finished coil is surrounded by a protective covering, after which binding bands are passed through the sleeve to enclose the coil and the protective rings, and tightened to form said parcel. The support rings are removed from the finished parcel to be used for manufacturing further coils. The finished parcel is delivered as it is to a work place, where another tool is mounted on the parcel to prepare for unwinding the object. The second tool also has two parallel support rings with centering elements facing each other. By clamping the parcel between the support rings and centering the parcel with the aid of their centering elements, a rotatable unit is obtained which can then be stored for free rotation about a horizontal or vertical axis of rotation in a special unwinding device. After cutting the straps and removing the protective covering, the object is exposed for unwinding.
When using the handling system described in the above-mentioned specification SE-9101042-1 for hosing and flexible tubing for fibre optic cable, for instance, it has been found that the parcel manufactured is relatively expensive and unnecessarily strong and thus has relatively high weight. A contributory reason for this is that, as mentioned earlier for wooden drums, a core is required, in this case a sleeve with a diameter of about 1 m and protective rings with a diameter of up to about 2.5 m.
The object of the invention is to eliminate the problems associated with the use of coils and wooden drums and improve the known advantageous handling system for continuous flexible objects so that products such as hosing and flexible tubing can be delivered in the form of parcels at a lower, acceptable cost, the products being sufficiently but not excessively strong, requiring less material and thereby having reduced weight.
The method according to the invention is characterized in that the end portions of a predetermined number of longitudinal support elements of equal length are brought into engagement with two flat, parallel end rings via corresponding recesses therein, located close to an inner, circular, concentric support surface which surrounds a central opening into which the recesses open, so that the end surfaces of the support elements coincide with the outer sides of the end rings, and the inner sides of the support elements coincide with the circular support surface to form said core, whereupon the centering elements of said support rings are inserted in said opening to actively press against the circular support surfaces and the inner sides of the support elements.
The core according to the invention is characterized in that it comprises a predetermined number of longitudinal support elements of equal length with end portions, parallel end surfaces and outer and inner sides; and two flat, parallel end rings each having a central opening, an inner circular concentric support surface which surrounds the central opening and has a predetermined radius, and a number of recesses corresponding to the number of support elements, which recesses are arranged in connection with the support surface and open towards the opening, the end portions of the support elements being in engagement with the recesses to keep the end rings parallel to each other and hold the support elements in axial position perpendicular to the end rings, the inner sides of the support elements being arranged to coincide with the support surfaces of the end rings and the end surfaces of the support elements with the outer sides of the end rings.